Communication system, program, and communication method

Abstract

To provide a communication system, a program, and a communication method that can ensure the reliability of wireless communication even when a communication environment changes.SOLUTION: A communication system 100 includes a route information acquisition unit 104 that acquires planned route information, a base station information acquisition unit 105 that acquires base station information, an HO frequent area acquisition unit 107 that acquires information regarding an HO frequent area where handovers are predicted to occur frequently, an arrival time prediction unit 108 that predicts the scheduled arrival time when its own vehicle 81 will arrive at the HO frequent area, and a communication setting unit 110 that sets the connection destination for wireless communication by a wireless communication unit 24. The communication setting unit 110 fixes a connection destination for wireless communication to a fixed connection destination, which is a single connection destination, for the HO frequent area indicated by the HO frequent area information acquired by the HO frequent area acquisition unit 107 by the scheduled arrival time.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a communication system, a program, and a communication method. [Background technology]

[0002] Conventionally, there are known technologies for wirelessly communicating various data with the outside in order to execute various vehicle functions such as autonomous driving. For example, Patent Document 1 describes a technology for determining whether to continue autonomous driving based on communication status information when communication with an autonomous driving assistance center is interrupted. Furthermore, Patent Document 2 describes a technology for, when there is a data gap, generating assistance data by complementing the data gap with previously received information and outputting the data to a driving assistance device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-71753 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-173904 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 determines the communication status based on whether or not there is a communication interruption, and has the problem that it is not possible to grasp the deterioration of communication quality until a communication interruption occurs. In Patent Document 2, when data loss occurs, the data loss is compensated for and reliability is evaluated using data loss count information, which results in unreliable data transmission and reception and also has the problem that it is not possible to grasp the deterioration of communication quality until data loss occurs. Therefore, there is room for improvement in terms of ensuring communication reliability.

[0005] An object of the present invention is to provide a communication system, a program, and a communication method that can ensure the reliability of wireless communication even when the communication environment changes. [Means for solving the problem]

[0006] (1) A communication system is a communication system equipped with a wireless communication unit mounted on a mobile body and performing wireless communication with a base station, wherein route information regarding a route along which the mobile body is scheduled to travel is generated based on input information, and the system is equipped with: a route information acquisition unit that acquires the route information; a base station information acquisition unit that acquires base station information including location information of each of a plurality of base stations that cover the communication area of ​​the route included in the acquired route information; a handover frequent area acquisition unit that acquires information regarding a handover frequent area on the route included in the route information where handovers are predicted to occur frequently, in which the base station to which the wireless communication unit is currently connected is switched to another wireless communication connection destination; an arrival time prediction unit that predicts the arrival time of the mobile body in the handover frequent area; and a communication setting unit that sets the wireless communication connection destination by the wireless communication unit, wherein the communication setting unit fixes the wireless communication connection destination to one connection destination for the handover frequent area indicated by the information acquired by the handover frequent area acquisition unit by the predicted arrival time.

[0007] (2) In the communication system described in (1), the one connection destination fixed by the communication setting unit is the base station that is predicted to have the most number of wireless communication connections due to handover in the handover frequent area.

[0008] (3) In the communication system described in (1), the one connection destination fixed by the communication setting unit is the base station in the handover frequent area with the strongest time average received radio wave strength received by the wireless communication unit when the wireless communication is connected.

[0009] (4) In the communication system described in (1), the one connection destination fixed by the communication setting unit is the base station that is predicted to have the smallest variation in the received radio wave strength received by the wireless communication unit each time wireless communication is connected in the frequent handover area, among base stations that are predicted to repeatedly connect and disconnect wireless communication in the frequent handover area.

[0010] (5) In the communication system described in (1), the one connection destination fixed by the communication setting unit is the base station in the handover frequent area in which the wireless communication unit is predicted to receive a radio wave strength equal to or greater than a predetermined radio wave strength for the longest time.

[0011] (6) In the communication system described in (1), the one connection destination fixed by the communication setting unit is a connection destination of a communication method in which handover does not occur in the handover frequent area.

[0012] (7) In the communication system described in (6), the communication method that does not cause handover is a communication method suitable for multi-access edge computing, such as V2I, V2V, or a method that uses satellite communication.

[0013] (8) The communication system described in any one of (1) to (7) includes an information processing device having the route information acquisition unit, the base station information acquisition unit, the handover frequent area acquisition unit, the arrival time prediction unit, and the communication setting unit, and a communication device having the wireless communication unit that performs bidirectional communication with an external communication device and the information processing device.

[0014] In the communication system described in (9) and (8), the information processing device is capable of communicating with the communication device, an in-vehicle sensor that detects the movement information of the mobile body, an outside sensor that detects the surrounding conditions of the mobile body, and an input / output device that accepts input operations by the driver of the mobile body and outputs information to the driver, and generates the route information, predicts the areas where handovers occur frequently, and predicts the arrival time based on information obtained from the communication device, the in-vehicle sensor, the outside sensor, and the input / output device.

[0015] (10) In the communication system described in (9), the input / output device accepts an input operation by the driver of a plurality of point information used in generating the route information by the information processing device, and transmits the information to the information processing device.

[0016] (11) The program is a program to be executed by a computer of a communication system that is mounted on a mobile body and has a wireless communication unit that communicates wirelessly with a base station, and that generates route information regarding a route along which the mobile body is scheduled to travel based on input information, and that includes: a route information acquisition process that acquires the route information; a base station information acquisition process that acquires base station information including location information of each of a plurality of base stations that cover the communication area of ​​the route included in the acquired route information; a handover frequent area acquisition process that acquires information regarding a handover frequent area on the route included in the route information where handovers are predicted to occur frequently, in which the base station to which the wireless communication unit is currently connected is switched to another wireless communication connection destination; an arrival time prediction process that predicts the arrival time of the mobile body in the handover frequent area; and a communication setting process that sets the wireless communication connection destination by the wireless communication unit, wherein in the communication setting process, the wireless communication connection destination is fixed to one connection destination for the handover frequent area indicated by the information acquired in the handover frequent area acquisition process by the predicted arrival time.

[0017] (12) A communication method is a communication scheme applied to a communication system equipped with a wireless communication unit mounted on a mobile body and communicating wirelessly with a base station, and includes a route information acquisition step for generating route information regarding a route along which the mobile body is scheduled to travel based on input information, and acquiring the route information; a base station information acquisition step for acquiring base station information including location information of each of a plurality of base stations covering the communication area of ​​the route included in the acquired route information; a handover frequent area acquisition step for acquiring information regarding a handover frequent area on the route included in the route information where handovers are expected to occur frequently, in which the base station to which the wireless communication unit is currently connected is switched to another wireless communication connection destination; an arrival time prediction step for predicting the arrival time of the mobile body in the handover frequent area; and a communication setting step for setting the wireless communication connection destination by the wireless communication unit, wherein in the communication setting step, the wireless communication connection destination is fixed to one connection destination for the handover frequent area indicated by the information acquired in the handover frequent area acquisition step by the predicted arrival time. [Effects of the Invention]

[0018] According to the present invention, the reliability of wireless communication can be ensured even when the communication environment changes. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram illustrating a communication system according to an embodiment of the present invention and an external communication device that performs wireless communication with the communication system. [Figure 2] 1 is a schematic diagram illustrating an example of a communication system according to an embodiment of the present invention and a road to which the communication system is applied. [Figure 3] 1 is a block diagram showing a hardware configuration of a communication device in a communication system according to an embodiment of the present invention. [Figure 4] 1 is a block diagram showing a hardware configuration of an information processing device in a communication system according to an embodiment of the present invention. [Figure 5]1 is a schematic diagram showing an example of a situation in which handovers frequently occur between a communication system and a plurality of base stations in an area where handovers frequently occur. [Figure 6] 1 is a block diagram showing a configuration of functional blocks of a communication device in a communication system according to an embodiment of the present invention. [Figure 7] 1 is a block diagram showing a functional block configuration of an information processing device in a communication system according to an embodiment of the present invention; [Figure 8] FIG. 2 is a sequence diagram showing an example of a flow up to wireless communication control processing in a communication system according to an embodiment of the present invention. [Figure 9] 5 is a flowchart illustrating an example of a wireless communication control process executed by a communication processing device according to an embodiment of the present invention. [Figure 10] 10 is a flowchart showing an example of a frequent HO area prediction process of the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 11] 10 is a flowchart showing an example of an HO compatible process of the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 12] 12 is a flowchart showing an example of a process, different from that shown in FIG. 11, of the HO compatible process in the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 13] 13 is a schematic diagram showing the state of communication between a communication system and a base station in an area where HO frequently occurs when the situation shown in FIG. 5 is predicted and the HO handling process shown in FIG. 12 is executed. FIG. [Figure 14] 13 is a flowchart showing an example of a process different from that shown in FIGS. 11 and 12 in the HO compatible process of the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 15] 1 is a schematic diagram showing an example of a situation in which handovers frequently occur between a communication system and a plurality of base stations in an area where handovers frequently occur. [Figure 16]16 is a schematic diagram showing the state of communication between a communication system and a base station in an area where HO frequently occurs when the situation shown in FIG. 15 is predicted and the HO handling process shown in FIG. 14 is executed. FIG. [Figure 17] 15 is a flowchart showing an example of HO compatible processing, different from that shown in FIGS. 11, 12, and 14, in the wireless communication control processing executed by the communication processing device according to one embodiment of the present invention. [Figure 18] 18 is a flowchart showing an example of HO compatible processing, different from that shown in FIGS. 11, 12, 14, and 17, in the wireless communication control processing executed by the communication processing device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a communication system 100 will be described as an example of a communication system according to an embodiment of the present invention. Fig. 1 is a schematic diagram showing the communication system 100 and an external communication device 7 that performs wireless communication with the communication system 100. Fig. 2 is a schematic diagram showing an example of the communication system 100 and a road 83 to which the communication system 100 is applied.

[0021] The communication system 100 is a system that is mounted on a moving object 8 and that wirelessly communicates various data with an external communication device 7 in order to execute multiple functions of the moving object 8. Examples of the moving object 8 include a vehicle and a drone. The moving object 8 may be a moving object with a person on board, or may be a moving object without a person on board, such as an unmanned vehicle or an unmanned aerial vehicle. In this embodiment, the communication system 100 mounted on the moving object 8 that is a vehicle will be described as an example. Note that, among the moving objects 8 that are vehicles, the moving object 8 that is mounted with the communication system 100 is referred to as the host vehicle 81, and the moving object 8 that is another vehicle as seen from the host vehicle 81 is referred to as the other vehicle 82.

[0022] The host vehicle 81 is, for example, an autonomously controlled or remotely controlled automatically driving vehicle. The host vehicle 81 is configured to be able to wirelessly communicate with the external communication device 7. The host vehicle 81 may be, for example, a vehicle that performs automatic driving based on estimated position information of the host vehicle 81 and map information about the surroundings of the host vehicle 81. Furthermore, for example, the host vehicle 81 may be a vehicle that performs automatic driving based on a control signal from a remote control center or the like.

[0023] The various functions of the mobile object 8 may be, for example, functions related to autonomous driving, functions related to driving assistance other than autonomous driving, functions related to calls with the outside world, or functions related to entertainment such as videos and games. The functions related to autonomous driving may be, for example, a collision safety function for avoiding a collision with an obstacle or another vehicle 82, a function for autonomously controlling the host vehicle 81, or a function for remotely controlling the host vehicle 81. Data required for the function for autonomously controlling the host vehicle 81 may be, for example, route information along which the host vehicle 81 travels under autonomous control, vehicle surroundings information indicating the conditions around the host vehicle 81, and driving information such as the speed of the host vehicle 81. Data required for the function for remotely controlling the host vehicle 81 may be vehicle surroundings information or a control signal for controlling the driving of the host vehicle 81. In the following description, the functions of the mobile object 8 are referred to as vehicle functions.

[0024] Before describing the communication system 100, an external communication device 7 that performs wireless communication with the communication system 100 will be described.

[0025] Examples of the external communication device 7 include a control server 71, a base station 72, a satellite system 73, a drone 74, a communication device (not shown) of another vehicle 82, a roadside device 75, and a communication terminal carried by a pedestrian. The communication system 100 performs V2X (vehicle-to-everything) communication with these devices, which includes various communication methods such as V2N (vehicle-to-network) communication, V2V (vehicle-to-vehicle) communication, V2I (vehicle-to-infrastructure) communication, V2D (vehicle-to-device) communication, and V2P (vehicle-to-pedestrian) communication.

[0026] The base station 72 performs V2N communication by wirelessly communicating with various devices such as communication devices of mobile objects 8 moving on a road 83. The multiple base stations 72 are installed in different communication areas and are communicably connected to the control server 71 and other base stations 72 via a communication network NW. A communication area refers to a geographical range in which each base station 72 is responsible for communication with each mobile object 8. In the example shown in FIG. 2, base stations 72A and 72B, which are multiple base stations 72, are installed at intervals.

[0027] The base station 72 transmits data acquired through wireless communication with mobile objects 8 traveling within the communication area and various devices to the control server 71 via the communication network NW, or directly to the communication device of the mobile object 8.

[0028] Examples of communication networks NW include mobile communication networks operated by various communication carriers, core networks that connect mobile communication networks, and wide area networks (WANs) that include private networks and the Internet.

[0029] The control server 71 is communicably connected to external communication devices 7 such as a plurality of base stations 72 via a communication network NW, and has the function of acquiring various data from the external communication devices 7 and storing and managing the data in a database or the like. Information about the base stations 72 managed by the control server 71 includes, for example, identification information for each base station 72 and communication load-related data such as communication traffic within the communication area of ​​each base station 72 and the number of connections of mobile units 8 and the like that are wirelessly communicating with each base station 72. The control server 71 manages current and past communication load-related data for the base stations 72.

[0030] The communication system 100 receives various data from the control server 71. The information received from the control server 71 includes, for example, map information including the route along which the mobile object 8 travels, including roads 83, data relating to the current and past communication loads of the base stations 72, position information of the mobile object 8, control signals for remotely controlling the mobile object 8, and various data required for autonomous control of the mobile object 8, and the like, which is then transmitted to the communication system 100. The map information includes position information of the base stations 72, buildings, structures, and the like located near the route.

[0031] The satellite system 73 may be, for example, a navigation satellite, a low-earth orbit satellite, a geostationary orbit satellite, or the like constituting a global navigation satellite system (GNSS) such as a global positioning system (GPS) or a quasi-zenith satellite system, or a meteorological satellite. The navigation satellite satellite system 73 transmits GNSS signals indicating location information to the ground, while the meteorological satellite system 73 transmits meteorological information including weather information such as clear skies, cloudy skies, and rainy skies, and rainfall information to the ground. The low-earth orbit satellite or geostationary orbit satellite satellite system 73 constitutes a non-terrestrial network (NTN) and enables wireless communication using 5G communication standards. The satellite system 73 also transmits satellite images and the like that provide traffic information, such as images of roads 83 on which the mobile unit 8 travels. By analyzing the satellite images, the location information of radio wave blocking objects, such as buildings and the mobile unit 8, that block radio waves can be identified. The satellite system 73 may transfer data acquired from the control server 71, the base station 72, the drone 74, the roadside device 75, the communication device of the other vehicle 82, etc. to the communication system 100.

[0032] The drone 74 transmits, for example, images including a road 83 on which the moving object 8 is traveling to the control server 71, the base station 72, the roadside device 75, the communication system 100, etc. The drone 74 constitutes a non-terrestrial network (NTN). For example, the drone 74 may transfer data acquired from the control server 71, the base station 72, the satellite system 73, the roadside device 75, the communication device of the other vehicle 82, etc. to the communication system 100.

[0033] The communication device of the other vehicle 82 communicates with the communication devices of other moving bodies 8, including the vehicle itself 81, using V2V communication or V2N communication via a base station 72, and may transmit data indicating the wireless communication status, such as the amount of communication with the outside world, as well as its own location information, identification information, etc.

[0034] The roadside units 75 are also called RSUs (road side units) or the like. The roadside units 75 are installed in different communication areas around (on the roadside of) a road 83. A communication area refers to the range in which each roadside unit is responsible for communication with each mobile object 8, and indicates, for example, a geographical range set along the road 83.

[0035] The roadside unit 75 provides a V2X (vehicle-to-everything) communication service by wirelessly communicating with communication devices of mobile objects 8 traveling on the road 83 and various devices present in the vicinity. The roadside unit 75 also transmits data acquired through wireless communication with mobile objects 8 traveling within the communication area and various devices to the control server 71 via the communication network NW, or directly to the communication devices of the mobile objects 8.

[0036] A communication terminal carried by a pedestrian or the like (hereinafter referred to as a pedestrian communication terminal) performs wireless communication with other external communication devices 7 including a base station 72. The pedestrian communication terminal may perform V2P communication with a communication device of a mobile object 8 including the vehicle 81, or may relay wireless communication between the communication device of the mobile object 8 and the base station 72.

[0037] As shown in FIG. 1, the communication system 100 is mounted on a moving object 8, and includes a communication processing device 6, an in-vehicle sensor 4, and an outside-vehicle sensor 5.

[0038] The in-vehicle sensor 4 is a sensor for detecting driving information such as the speed, acceleration, and angular velocity of the host vehicle 81. Examples of the in-vehicle sensor 4 include a vehicle speed sensor that detects the speed of the host vehicle 81, an acceleration sensor that detects the acceleration of the host vehicle 81, and a yaw rate sensor that detects the yaw angular velocity of the host vehicle 81.

[0039] The exterior sensor 5 is a device for detecting information about the surroundings of the host vehicle 81. The exterior sensor 5 may be, for example, a radar such as a millimeter-wave radar, a LiDAR (light detection and ranging), or a camera. The camera detects information about the surroundings of the host vehicle 81 by capturing still or video images of the surroundings of the host vehicle 81. The millimeter-wave radar or LiDAR detects the distance, direction, relative speed, etc. of objects present around the host vehicle 81 based on transmission waves transmitted to the surroundings of the host vehicle 81 and reflected received waves. The exterior sensor 5 of this embodiment irradiates the surroundings with millimeter waves or laser light and detects surrounding objects as point cloud data, thereby detecting the positions, shapes, etc. of surrounding objects with high accuracy. The exterior sensor 5 transmits the detected point cloud data to the information processing device 1. Position information of radio wave blocking objects such as buildings and other vehicles 82 present around the host vehicle 81 can be obtained from the point cloud data detected by the exterior sensor 5.

[0040] The communication processing device 6 includes an input / output device (HMI; Human Machine Interface) 3, a communication device 2, and an information processing device 1. In this embodiment, the HMI 3, the communication device 2, and the information processing device 1 are separate entities, but they may also be integrated. By separating the communication device 2 from the information processing device 1, etc., the processing in the device can be specialized for wireless communication with the external communication device 7, allowing for smoother wireless communication.

[0041] The HMI 3 is an interface that receives information input by the driver of the vehicle 81 and outputs the information to the driver. The HMI 3 may be configured to include, for example, buttons, a display, a speaker, etc. The information that the driver inputs to the HMI 3 may be, for example, point information for generating route information along which the vehicle 81 is scheduled to travel. The point information may be the current location of the vehicle 81, the starting point of the planned route, the destination point, stop-off points along the route from the starting point to the destination point, and evacuation points. An evacuation point is, for example, an area where the vehicle 81, while autonomously driving, makes an emergency stop in the event of an abnormality, etc. Note that there may be multiple stop-off points and evacuation points.

[0042] The communication device 2 is a part that performs wireless communication with the external communication device 7. The communication device 2 may be a device that handles either or both of telematics and infotainment information. The communication device 2 of this embodiment transmits and receives data to and from the external communication device 7 via multiple wireless lines using various communication methods. The data acquired by the communication device 2 is transmitted to the information processing device 1.

[0043] Here, the hardware configuration of the communication device 2 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the hardware configuration of the communication device 2.

[0044] The communication device 2 includes a computer 28, a storage unit 23, a wireless communication unit 24, and an I / F unit 25. These units are connected by a bus 27 and the like. As the bus 27, for example, an in-vehicle communication means such as a wire harness for electrical communication or an optical fiber cable for high-speed optical communication can be used.

[0045] The computer 28 includes a processor 20 and a read-only memory (ROM) 21 and a random-access memory (RAM) 22 as main storage devices. The processor 20 may be a central processing unit (CPU), a microprocessing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 20 may be a combination of these. The processor 20 may also be a combination of these with a hardware accelerator or the like. The processor 20 controls each component to realize various functions of the communication device 2 based on programs such as firmware, system software, and application software stored in the ROM 21, the RAM 22, or an auxiliary storage device that is part of the storage unit 23. Note that some or all of the programs may be incorporated into the circuitry of the processor 20.

[0046] The storage unit 23 is a storage area for various programs and various data for causing the hardware group to function as the communication device 2, and can be configured with a ROM, RAM, flash memory, a solid-state drive (SSD), a hard disk drive (HDD), etc. Specifically, the storage unit 23 stores programs and the like for causing the computer 28 to execute each function of this embodiment.

[0047] The wireless communication unit 24 executes processing for the communication device 2 to perform wireless communication with the external communication device 7. The wireless communication unit 24 is configured to be able to transmit data using a plurality of communication methods, such as V2N communication in which the wireless communication destination is a base station 72, V2I communication in which the wireless communication destination is a roadside device 75, V2V communication in which the wireless communication destination is a communication device of another vehicle 82, V2D communication in which the wireless communication destination is a drone 74, V2P communication in which the wireless communication destination is a communication device carried by a pedestrian, communication using NTN in which the wireless communication destination is a satellite system 73, and communication to which multi-access edge computing (MEC) can be applied.

[0048] The I / F unit 25 is a wired communication interface for the communication device 2 to communicate with the information processing device 1.

[0049] The GNSS unit 26 includes an antenna and receives GNSS signals, etc. The GNSS unit 26 transmits the received GNSS signals to the processor 20. The GNSS unit 26 may transmit the received GNSS signals to the information processing device 1 via the I / F unit 25.

[0050] The following describes the information processing device 1. The information processing device 1 acquires and processes various information from an in-vehicle sensor 4, an out-vehicle sensor 5, a communication device 2, and an HMI 3. The information processing device 1 controls the communication device 2 and functions of the vehicle 81 related to autonomous driving and the like through wireless communication with an external communication device 7.

[0051] Next, an example of the hardware configuration of the information processing device 1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the hardware configuration of the information processing device 1.

[0052] The information processing device 1 includes a computer 16, a storage unit 13, and an I / F unit 14. These units are connected by a bus 15 and the like. The bus 15 may be, for example, an in-vehicle communication means such as a wire harness for electrical communication or an optical fiber cable for high-speed optical communication.

[0053] The computer 16 includes a processor 10 and a read-only memory (ROM) 11 and a random-access memory (RAM) 12 as main storage devices. The processor 10 may be a central processing unit (CPU), a microprocessing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 10 may be a combination of these. The processor 10 may also be a combination of these with a hardware accelerator or the like. The processor 10 controls each unit to realize various functions of the information processing device 1 based on programs such as firmware, system software, and application software stored in the ROM 11, the RAM 12, or an auxiliary storage device that is part of the storage unit 13. Note that some or all of the programs may be incorporated into the circuitry of the processor 10.

[0054] The storage unit 13 is a storage area for storing various programs and various data for causing the hardware group to function as the information processing device 1, and can be configured with a ROM, RAM, flash memory, a solid-state drive (SSD), a hard disk drive (HDD), or the like. Specifically, the storage unit 13 stores programs for causing the computer 16 to execute each function of this embodiment, and information related to vehicle functions (hereinafter referred to as vehicle function-related information). Examples of the vehicle function-related information include details of vehicle functions such as collision safety functions, details of data transmitted and received via wireless communication, parameters related to communication quality and data processing, and their priorities, which will be described later.

[0055] The I / F unit 14 is a wired communication interface that enables the information processing device 1 to communicate with the communication device 2, the in-vehicle sensors 4, the outside-vehicle sensors 5, or the ECU 84 of the vehicle 81. The information processing device 1 uses the I / F unit 14 to communicate with the in-vehicle sensors 4, the outside-vehicle sensors 5, the ECU 84, etc. via an on-vehicle LAN including, for example, Ethernet (registered trademark), which is implemented by CAN (Controller Area Network) communication, LIN (Local Interconnect Network) communication, electrical communication, or optical communication.

[0056] 2, for example, when a vehicle 81 within a communication area A of a base station 72A is traveling toward a communication area A of a base station 72B, handover must be performed to continue wireless communication, and the communication connection must be switched from base station 72A to 72B. The handover is performed, for example, in a handover area (hereinafter referred to as an HO area) B, which is an area where the communication areas A of the base stations 72 overlap.

[0057] During handover, data can be sent and received after a connection is established between the communication device 2 of the vehicle 81 and the new wireless communication connection destination, such as for transferring information, so there is a possibility that a delay in data transmission speed may occur during handover.

[0058] Here, for example, as shown in FIG. 5, if base stations 72B and 72C are located relatively close to each other around the route traveled by the host vehicle 81, the communication device 2 of the host vehicle 81 may repeatedly connect and disconnect alternately to these two base stations 72B and 72C. For example, the communication device 2 of the host vehicle 81 may connect to base station 72B, then connect to base station 72A, and then connect to base station 72B again as shown in FIG. 5. After that, the connection destination switches between base stations 72C, 72B, 72C, and 72B. That is, handovers are repeated between base station 72B and base station 72C, resulting in frequent handovers. Frequent handovers increase the possibility of delays in data transmission speed, accumulate delay times, and degrade communication quality in an area where handovers occur frequently (hereinafter referred to as a frequent handover area). Note that a frequent handover area refers to an area where handovers are repeated between two or more specific base stations 72 at a certain time or within a certain area, as a certain period of time elapses or as the vehicle moves.

[0059] In this embodiment, by fixing the wireless communication connection destination to one in an area where HO occurs frequently, frequent handovers can be avoided, data loss and delays in data transmission speed can be reduced, and communication reliability can be ensured.

[0060] Next, various functions that are realized by the processor 20 of the communication device 2 and that execute wireless communication control processing will be described with reference to FIG.

[0061] As shown in FIG. 6, the processor 20 of the communication device 2 includes a self-position estimation unit 201, a communication mode switching unit 202, and a communication control unit 203.

[0062] The self-position estimation unit 201 executes a process of estimating position information (hereinafter referred to as self-position information) of the vehicle 81. The self-position estimation unit 201 may estimate the self-position information based on, for example, map information, a GNSS signal, or the like received from the control server 71.

[0063] The communication mode switching unit 202 executes a process of switching the wireless communication mode between a normal mode and an HO compatible mode based on a control signal from the information processing device 1. The normal mode is a mode in which data required to execute each of a plurality of functions of the vehicle 81 is transmitted over a single predetermined wireless line. The HO compatible mode is a communication mode compatible with wireless communication in an area where HO occurs frequently, and is a communication mode in which the wireless communication connection destination is fixed to one connection destination based on transmission control information transmitted from the information processing device 1 so that handover does not occur.

[0064] The communication control unit 203 executes processing to control wireless communication between the communication device 2 and the external communication device 7 and communication between the communication device 2 and the information processing device 1. The communication control unit 203 controls wireless communication with the external communication device 7 in accordance with the communication mode switched by the communication mode switching unit 202.

[0065] Next, various functions realized by the processor 10 of the information processing device 1 will be described with reference to FIG.

[0066] As shown in FIG. 7, the processor 10 of the information processing device 1 includes a location information acquisition unit 101, a map information acquisition unit 102, a position information acquisition unit 103, a route information acquisition unit 104, a base station information acquisition unit 105, a communication environment information acquisition unit 106, a frequent HO area acquisition unit 107, an arrival time prediction unit 108, and a communication setting unit 110.

[0067] The point information acquisition unit 101 executes a process of acquiring point information. For example, the point information acquisition unit 101 executes a process of acquiring point information input by the driver from the HMI 3. The point information acquired from the HMI 3 may be position information such as a departure point of a planned route of the vehicle 81, a destination point, a stop-off point on the route from the departure point to the destination point, an evacuation point, etc. The point information acquisition unit 101 may also acquire self-position information of the current location acquired by the position information acquisition unit 103 as point information.

[0068] The map information acquisition unit 102 executes a process of acquiring map information including at least the road 83 on which the vehicle 81 is traveling and the road 83 on which the vehicle 81 is scheduled to travel. The map information acquisition unit 102 acquires the map information from the control server 71 via the communication device 2, for example.

[0069] The position information acquisition unit 103 executes a process of acquiring self-position information of the current location (hereinafter referred to as current location information). The position information acquisition unit 103 may acquire, for example, current location information of the vehicle 81 estimated by the self-position estimation unit 201 of the communication device 2. Alternatively, for example, the position information acquisition unit 103 may estimate current location information of the vehicle 81 based on map information, a GNSS signal, etc. acquired by the map information acquisition unit 102, and acquire the estimated information as the current location information. Alternatively, for example, the position information acquisition unit 103 may acquire vehicle surroundings information such as point cloud information around the vehicle 81 from the external vehicle sensor 5, acquire map information from the control server 71 via the communication device 2, and compare the vehicle surroundings information with the map information to estimate the position information of the vehicle 81, thereby acquiring the self-position information.

[0070] The route information acquisition unit 104 executes a process of acquiring planned route information regarding a route along which the vehicle 81 is scheduled to travel. The route information acquisition unit 104 may generate route information based on the point information acquired by the point information acquisition unit 101, the map information acquired by the map information acquisition unit 102, the current location information acquired by the position information acquisition unit 103, and the like, and acquire the generated information as planned route information. As a method of generating the planned route information, for example, a starting point or the current location, a destination point, a stop-off point, and an evacuation point may be identified on a map indicated by the map information, and roads 83 connecting these may be generated as planned route information. Furthermore, for example, the route information acquisition unit 104 may acquire route information as planned route information from a car navigation device or the like that generates route information, or may acquire route information stored in the control server 71 from the control server 71 as planned route information.

[0071] The base station information acquisition unit 105 executes a process of acquiring base station information including the location information and identification information of each of the base stations 72 present on the route included in the planned route information and in the vicinity thereof. The base station information may also include an HO threshold, which is the received radio wave intensity at which a currently connected terminal switches its wireless communication connection to another base station 72 by handover.

[0072] The communication environment information acquisition unit 106 executes a process of acquiring, via the communication device 2, communication environment information about the road 83 and its surroundings, which is included in the planned route information acquired by the route information acquisition unit 104. The communication environment information acquisition unit 106 may acquire, for example, data related to communication loads, such as communication traffic in a communication area A covered by base stations 72 installed at each point on the road 83 included in the planned route information managed by the control server 71, and the number of connections to the base station 72 from communication devices of mobile objects 8 and communication terminals of pedestrians and the like that wirelessly communicate with the base station 72 (hereinafter, referred to as communication load-related data). Furthermore, for example, the communication environment information acquisition unit 106 may acquire communication load-related data, such as current communication traffic in the communication area A of the base station 72, or communication load-related data, such as communication traffic in the same time period in the past. For example, the communication environment information acquisition unit 106 may acquire position information and wireless communication volume of each moving body 8 from a communication device of another vehicle 82 traveling on a road 83 included in the planned route information by V2V communication with the other vehicle 82 or V2N2V communication via the base station 72 or the communication network NW. For example, the communication environment information acquisition unit 106 may acquire an image including the road 83 indicated in the planned route information from the satellite system 73 or the drone 74, and extract information about traffic conditions such as traffic volume of the moving body 8, position information of the moving body 8 and radio wave shielding objects such as buildings, from the acquired image. For example, weather information may be acquired from the satellite system 73, which is a meteorological satellite. For example, the communication environment information acquisition unit 106 may acquire communication volume between the pedestrian communication terminal of a pedestrian walking on the road 83 included in the planned route information and the base station 72, etc., from the base station 72, the pedestrian communication terminal, etc.

[0073] The HO frequent occurrence area acquisition unit 107 executes a process of acquiring information about the predicted HO frequent occurrence area (hereinafter referred to as HO frequent occurrence area information). Examples of the HO frequent occurrence area information include location information of the HO frequent occurrence area.

[0074] The HO frequent area acquisition unit 107 may acquire HO frequent area information from, for example, the control server 71 or the base station 72, as predetermined information. Alternatively, the HO frequent area acquisition unit 107 may acquire HO frequent area information by predicting areas where handovers frequently occur based on various information. In this case, the HO frequent area acquisition unit 107 may predict the HO frequent area based on base station information. For example, the HO frequent area acquisition unit 107 may predict an area where the distances to two or more different base stations 72 are approximately equal based on the location information of the base stations 72 indicated in the base station information as the HO frequent area. Alternatively, the HO frequent area acquisition unit 107 may predict an area where the predicted values ​​of the received radio wave strength of radio waves received by the wireless communication unit 24 from multiple base stations 72 are comparable and the received radio wave strength is near an HO threshold as the HO frequent area. In this case, the predicted value of the received radio wave strength may be predicted using, for example, current communication traffic or past communication traffic during the same time period.

[0075] When an HO frequent area is acquired by the HO frequent area acquisition unit 107, the arrival time prediction unit 108 predicts the scheduled arrival time, which is the time when the host vehicle 81 will arrive in the HO frequent area. The arrival time prediction unit 108 may, for example, acquire driving information such as the vehicle speed of the host vehicle 81 from the in-vehicle sensor 4 and predict the scheduled arrival time based on the driving information. The arrival time prediction unit 108 may predict the scheduled arrival time using at least one of the legal speed limit of the road 83 indicated by the scheduled route information, the average speed of the traveling mobile object 8, traffic conditions, and the vehicle speed of the host vehicle 81.

[0076] When the frequent HO area acquisition unit 107 acquires the frequent HO area information, the communication setup unit 110 executes a process of fixing the wireless communication destination in the frequent HO area to one destination (hereinafter referred to as fixed destination) before arriving at the frequent HO area. The communication setup unit 110 includes an HO connection information prediction unit 111, a destination selection unit 112, and an output processing unit 113.

[0077] The HO connection information prediction unit 111 predicts HO connection information such as the number of wireless communication connections (hereinafter referred to as communication connections) with the wireless communication unit 24 due to handover of each base station 72 in the HO frequent area (hereinafter referred to as the number of connections), the connection time, and the received radio wave strength (hereinafter referred to as RSSI at connection time) received by the wireless communication unit 24 during the communication connection.

[0078] The HO connection information prediction unit 111 acquires, for example, from the control server 71 or the base station 72, HO frequent base station information of each base station 72 that is expected to frequently perform handovers in the HO frequent area. Examples of the HO frequent base station information include the number of connections and connection times between each base station 72 in the HO frequent area and a communication device of a mobile unit 8 during the same time period as the past scheduled arrival time. The HO connection information prediction unit 111 may use the number of connections and connection times indicated by the HO frequent base station information of a base station 72 in the HO frequent area as the predicted number of connections and connection times of the base station 72.

[0079] The connection destination selector 112 executes a process of selecting a fixed connection destination. The connection destination selector 112 may select a fixed connection destination based on the HO connection information predicted by the HO connection information predictor 111.

[0080] For example, the connection destination selection unit 112 may select, as the fixed connection destination, the base station 72 having the largest number of connections predicted by the HO connection information prediction unit 111 among the multiple base stations 72 that will be the connection destination for wireless communication with the communication device 2 via handover in an HO frequent area.

[0081] Alternatively, for example, the connection destination selector 112 may select the base station 72 with the highest time average of the RSSI at connection predicted by the HO connection information predictor 111 as the fixed connection destination.

[0082] Alternatively, for example, the connection destination selection unit 112 may select, as the fixed connection destination, the base station 72 that is predicted to have the smallest variation in connection RSSI at each communication connection in the HO frequent area. In this case, for example, the connection destination selection unit 112 calculates the standard deviation of connection RSSI at each communication connection for one base station 72 that will be a connection destination for wireless communication with the communication device 2 via handover in the HO frequent area. Then, the connection destination selection unit 112 may select, as the fixed connection destination, the base station 72 with the smallest calculated standard deviation of RSSI from among the multiple base stations 72 that will be connection destinations for wireless communication with the communication device 2 via handover in the HO frequent area.

[0083] Furthermore, for example, the connection destination selection unit 112 may select, as a fixed connection destination, the base station 72 for which the connection RSSI is equal to or greater than the HO threshold for the longest period of time during communication connection in an HO frequent area.

[0084] The connection destination selection unit 112 may select a connection destination of a communication method that does not cause handover in an area where HO occurs frequently as a fixed connection destination. Examples of communication methods that do not cause handover include communication methods suitable for multi-access edge computing, V2I, V2V, and methods using satellite communication. That is, the connection destination selection unit 112 selects the roadside device 75 as the fixed connection destination in V2I communication, the communication device of the mobile object 8 as the fixed connection destination in V2V communication, the satellite system 73 or the drone 74 as the fixed connection destination in the method using satellite communication, and the edge server as the fixed connection destination in the communication method suitable for multi-access edge computing.

[0085] The output processing unit 113 transmits HO transmission control information to the communication device 2, which instructs the communication device 2 to fix the wireless communication destination in the frequent HO area to the fixed destination selected by the destination selection unit 112, before the vehicle 81 arrives at the frequent HO area. Upon receiving the HO transmission control information, the communication device 2 performs wireless communication only with the fixed destination without performing handover in the frequent HO area.

[0086] Next, an example of the processing flow by the communication processing device 6 in the communication system 100 from generating planned route information for the vehicle 81 to performing wireless communication with a fixed connection destination in the HO prediction area will be described with reference to Fig. 8. Fig. 8 is a sequence diagram showing an example of the processing flow from inputting location information by the driver to performing wireless communication with a fixed connection destination in the HO prediction area.

[0087] As shown in FIG. 8, in step S101, the HMI 3 receives location information such as a departure point and a destination point input by the driver of the vehicle 81, for example.

[0088] In step S102, the HMI 3 transmits the location information received in step S101 to the information processing device 1.

[0089] In step S103 , the communication device 2 transmits the map information received from the control server 71 to the information processing device 1 .

[0090] In step S104, the information processing device 1 generates planned route information based on the vehicle surroundings information of the vehicle 81 transmitted from the external sensor 5, the location information transmitted from the HMI 3 in step S102, and the map information transmitted from the communication device 2 in step S103.

[0091] In step S105, the communication device 2 transmits the base station information acquired from the control server 71 to the information processing device 1. The base station information transmitted from the communication device 2 in step S105 includes identification information and location information of the road 83 included in the planned route information and each of the multiple base stations 72 arranged in the vicinity thereof.

[0092] In step S106, the communication device 2 transmits the frequent HO area information acquired from the control server 71 or the base station 72 to the information processing device 1.

[0093] In step S107, the information processing device 1 predicts the scheduled arrival time at which the vehicle 81 will arrive in the frequent HO area based on the frequent HO area information transmitted from the communication device 2 in step S106 and the driving information of the vehicle 81 transmitted from the in-vehicle sensor 4, and transmits the predicted scheduled arrival time to the communication device 2.

[0094] In step S108, the information processing device 1 instructs the communication device 2 to acquire frequent HO base station information relating to a base station 72 that is located before the frequent HO area and is predicted to have frequent handovers in the frequent HO area.

[0095] In step S109 , the communication device 2 acquires the information on base stations where HO frequently occurs from the control server 71 or the base station 72 , and transmits the acquired information on base stations where HO frequently occurs to the information processing device 1 .

[0096] In step S110, the information processing device 1 selects a base station 72 as a fixed connection destination in the frequent HO area based on the frequent HO base station information.

[0097] In step S111, the information processing device 1 transmits HO transmission control information instructing that the wireless communication destination in the HO frequent area be fixed to the base station 72.

[0098] In step S112, the communication device starts communication with the base station 72, which is the fixed connection destination, in the HO frequent area.

[0099] Next, an example of wireless communication control processing executed by the communication processing device 6 will be described with reference to FIGS.

[0100] First, the overall flow of the wireless communication control process will be described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of the wireless communication control process executed by the communication processing device 6.

[0101] As shown in FIG. 9, in step S10, the processor 10 of the information processing device 1 executes a process of predicting an area where HO occurs frequently.

[0102] In step S21, the processor 10 determines whether or not an HO frequent area has been detected by the HO frequent area prediction process in step S10. If the processor 10 determines that an HO frequent area has been detected (step S21; YES), the processor 10 proceeds to step S22. On the other hand, if the processor 10 determines that an HO frequent area has not been detected (step S21; NO), the processor 10 ends the wireless communication control process.

[0103] In step S21, the processor 10 or 20 of the communication processing device 6 determines whether the host vehicle 81 has approached the HO frequent area acquired by the HO frequent area prediction process to within a predetermined distance. If the processor 10 or 20 determines that the host vehicle 81 has approached to within the predetermined distance (step S22; YES), the processor 10 or 20 proceeds to step S30. On the other hand, if the processor 10 or 20 determines that the host vehicle 81 has not approached to within the predetermined distance (step S22; NO), the processor 10 or 20 repeats the process of step S21 after a predetermined time has elapsed.

[0104] In step S30, the processor 10 and the processor 20 execute the HO handling process.

[0105] In step S23, the processor 10 or 20 of the communication processing device 6 determines whether the host vehicle 81 has passed through the HO prediction area and is a predetermined distance away from the HO prediction area. If the processor 10 or 20 determines that the host vehicle 81 has moved the predetermined distance away (step S23; YES), the processor 10 or 20 switches the communication mode of the communication device 2 from the HO-compatible mode to the normal mode (step S50), and then ends the wireless communication control process. On the other hand, if the processor 10 or 20 determines that the host vehicle 81 has not moved the predetermined distance away (step S23; NO), the processor 10 or 20 repeats the process of step S23 after a predetermined time has elapsed.

[0106] Next, the frequent HO area prediction process in step S10 of the wireless communication control process will be described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of the frequent HO area prediction process executed by the communications processing device 6.

[0107] As shown in FIG. 10, in step S11, the location information acquisition unit 101 of the processor 10 acquires location information such as the departure point and destination point of the vehicle 81 input by the driver of the vehicle 81 via the HMI 3 from the HMI 3.

[0108] In step S12, the map information acquisition unit 102 acquires map information transmitted from the control server 71 via the communication device 2, and the position information acquisition unit 103 acquires current position information of the vehicle 81 as its own position information.

[0109] In step S13, the route information acquisition unit 104 generates planned route information based on the location information, self-position information, and map information acquired in steps S11 and S12.

[0110] In step S14, the base station information acquisition unit 105 acquires base station information of the base stations 72 that exist on the route included in the planned route information generated in step S13 and in the vicinity thereof.

[0111] In step S15, the frequent HO occurrence area acquisition unit 107 predicts the frequent HO occurrence area. The frequent HO occurrence area acquisition unit 107 may predict the frequent HO occurrence area based on the base station information acquired in step S14, or may predict the frequent HO occurrence area based on the frequent HO occurrence area information acquired from the control server 71 or the base station 72.

[0112] In step S16, the processor 10 determines whether an HO frequent occurrence area has been detected by the HO frequent occurrence area prediction process. If the processor 10 determines that an HO frequent occurrence area has been detected (step S16; YES), the processor 10 proceeds to step S17. On the other hand, if the processor 10 determines that an HO frequent occurrence area has not been detected (step S16; NO), the processor 10 ends the HO frequent occurrence area prediction process.

[0113] In step S17, the arrival time prediction unit 108 acquires travel information including the vehicle speed of the host vehicle 81 from the in-vehicle sensor 4.

[0114] In step S18, the arrival time prediction unit 108 predicts the estimated arrival time at which the host vehicle 81 will arrive in the frequent HO area based on the vehicle speed acquired in step S18, the map information acquired in step S12, etc. Then, the processor 10 ends the frequent HO area prediction process.

[0115] Next, the HO response process in step S30 of the wireless communication control process will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the HO response process executed by the information processing device 1 and the communication device 2.

[0116] As shown in FIG. 11, in step S31, the HO connection information prediction unit 111 of the communication setting unit 110 acquires HO frequent base station information of each base station 72 that is predicted to repeatedly establish and disconnect wireless communication with the communication device 2 due to handover in the HO frequent area predicted in step S15.

[0117] In step S32, the connection destination selection unit 112 selects a fixed connection destination in the area where HO occurs frequently.

[0118] In step S33, the output processing unit 113 transmits HO transmission control information to the communication device 2 to instruct the communication device 2 to fix the wireless communication destination in the frequent HO area to the fixed connection destination selected in step S32. As a result, the communication device 2 performs wireless communication only with the fixed connection destination in the frequent HO area in accordance with the received HO transmission control information.

[0119] Next, an example of a processing flow of the HO handling processing that is different from the example shown in FIG. 11 will be described with reference to FIG.

[0120] As shown in FIG. 12, in step S31, the HO connection information prediction unit 111 of the communication setting unit 110 acquires HO frequent base station information of each base station 72 that is predicted to repeatedly establish and disconnect wireless communication with the communication device 2 due to handover in the HO frequent area predicted in step S15.

[0121] In step S34, the HO connection information prediction unit 111 predicts the number of connections for each base station 72 where handovers are predicted to occur frequently in the HO frequent area predicted in step S15. For example, the HO connection information prediction unit 111 may predict the number of connections for each base station 72 by obtaining the number of connections for each base station 72 from the control server 71.

[0122] In step S35, the connection destination selection unit 112 selects, as the fixed connection destination, the base station 72 with the highest number of connections predicted in step S34. For example, the connection destination selection unit 112 may select, as the fixed connection destination, the base station 72 with the highest number of connections among all the base stations 72 for which the HO connection information prediction unit 111 predicted the number of connections. For example, in the example shown in FIG. 5, it is assumed that the HO connection information prediction unit 111 predicted the number of connections to base station 72B to be four and the number of connections to base station 72C to be two. In this case, the connection destination selection unit 112 selects, as the fixed connection destination, the base station 72B with the number of connections predicted to be four, as shown in FIG. 13.

[0123] In step S36, the output processing unit 113 transmits HO transmission control information to the communication device 2 to instruct the communication device 2 to fix the wireless communication destination in the frequent HO area to the fixed connection destination selected in step S35. As a result, the communication device 2 performs wireless communication only with the fixed connection destination in the frequent HO area in accordance with the received HO transmission control information.

[0124] Next, an example of a processing flow of the HO handling processing that is different from the example shown in FIGS. 11 and 12 will be described with reference to FIG.

[0125] As shown in FIG. 14, in step S31, the HO connection information prediction unit 111 of the communication setting unit 110 acquires HO frequent base station information of each base station 72 that is predicted to repeatedly establish and disconnect wireless communication with the communication device 2 due to handover in the HO frequent area predicted in step S15.

[0126] In step S37, the HO connection information prediction unit 111 predicts the change in received radio wave intensity over time for each base station 72 where handovers are predicted to occur frequently in the HO frequent area predicted in step S15. Specifically, the HO connection information prediction unit 111 obtains a predicted value of the connection time for each communication connection with each base station 72 and a predicted value of the connection time RSSI that the communication device 2 receives during each communication connection.

[0127] In step S38, the connection destination selection unit 112 calculates the time average of the predicted value of the RSSI at connection for each base station 72 acquired in step S37, and selects the base station 72 with the highest calculated average value as the fixed connection destination. For example, in the example shown in Fig. 15, it is assumed that the predicted connection times during each communication connection with base station 72B and base station 72C and the predicted values ​​of the RSSI at connection during each communication connection predicted in step S37 are as follows (1) to (6). (1) Estimated connection time T0 and estimated RSSI value R0 for the first communication connection with the base station 72B (2) Estimated connection time T1 and estimated RSSI value R1 for the second communication connection with base station 72B (3) Estimated connection time T2 and estimated RSSI value R2 for the first communication connection with the base station 72C (4) Predicted connection time T3 and predicted RSSI value R3 for the third communication connection with base station 72B (5) Predicted connection time T4 and predicted RSSI value R1 at the time of connection for the second communication connection with base station 72C (6) Estimated connection time T5 and estimated RSSI value R5 for the fourth communication connection with base station 72B

[0128] The time average RB of the predicted value of the RSSI during communication connection with the base station 72B is calculated by the following equation (1). RB=(R2+R4) / (T2+T4)...Equation (1)

[0129] The time average RC of the predicted value of the RSSI during communication connection with the base station 72C is calculated by the following equation (2). RC=(R0+R1+R3+R5) / (T0+T1+T3+T5) Formula (2)

[0130] If the time average RC of the RSSI during connection when communicating with the base station 72C is greater than the time average RB of the RSSI during connection when communicating with the base station 72B, the connection destination selection unit 112 selects the base station 72C as a fixed connection destination. As a result, as shown in Fig. 16, while the vehicle 81 is traveling in an area where handovers frequently occur, the wireless communication unit 24 of the communication device 2 performs wireless communication only with the base station 72C, thereby preventing frequent handovers.

[0131] In step S39, the output processing unit 113 transmits HO transmission control information to the communication device 2 to instruct the communication device 2 to fix the wireless communication destination in the frequent HO area to the fixed connection destination selected in step S38. As a result, in accordance with the received HO transmission control information, the communication device 2 performs wireless communication only with the fixed connection destination in the frequent HO area.

[0132] 14, the connection destination selection unit 112 selects a fixed connection destination based on the time average of the RSSI at the time of connection, but it may also calculate the standard deviation of the received radio wave strength at the time of each communication connection for each base station 72 and select a fixed connection destination based on the calculated standard deviation. In other words, the connection destination selection unit 112 may select, as the fixed connection destination, the base station 72 with the smallest standard deviation of the received radio wave strength at the time of each communication connection from among multiple base stations 72 in an area where handovers frequently occur.

[0133] Next, an example of a processing flow of the HO handling processing that is different from the examples shown in FIGS. 11, 12, and 14 will be described with reference to FIG.

[0134] As shown in FIG. 17, in step S31, the HO connection information prediction unit 111 of the communication setting unit 110 acquires HO frequent base station information of each base station 72 that is predicted to repeatedly establish and disconnect wireless communication with the communication device 2 due to handover in the HO frequent area predicted in step S15.

[0135] In step S37, the HO connection information prediction unit 111 predicts the change in received signal strength over time for each base station 72 where handovers are predicted to occur frequently in the HO frequent area predicted in step S15. Specifically, the HO connection information prediction unit 111 obtains a predicted value of the connection time for each communication connection with each base station 72 and a predicted value of the connection time RSSI during each communication connection.

[0136] In step S40, the HO connection information prediction unit 111 acquires the HO reception signal strength information. For example, the HO connection information prediction unit 111 may acquire information on the HO reception signal strength information of each base station 72 that frequently occurs handover in an HO frequent area from the control server 71 or the base station 72.

[0137] In step S41, the connection destination selection unit 112 selects, as a fixed connection destination, the base station 72 that is predicted to have the longest time during which the connection RSSI during communication connection in the frequent HO area is equal to or greater than the HO threshold.

[0138] In step S42, the output processing unit 113 transmits HO transmission control information to the communication device 2 to instruct the communication device 2 to fix the wireless communication destination in the frequent HO area to the fixed connection destination selected in step S41. As a result, the communication device 2 performs wireless communication only with the fixed connection destination in the frequent HO area in accordance with the received HO transmission control information.

[0139] Next, an example of a processing flow of the HO handling processing that is different from the examples shown in FIGS. 11, 12, 14, and 17 will be described with reference to FIG.

[0140] 18, in step S43, the connection destination selection unit 112 selects a connection destination of a communication method that does not cause handover in an HO frequent area as a fixed connection destination. For example, the connection destination selection unit 112 may search for candidates for fixed connection destinations such as the roadside unit 75, the satellite system 73, the drone 74, etc., using map information acquired from the control server 71, vehicle surrounding information from the external sensor 5, information acquired through communication with the outside, etc., and select a fixed connection destination from the searched candidates.

[0141] In step S44, the output processor 113 transmits HO transmission control information to the communication device 2 to instruct the communication device 2 to fix the wireless communication destination in the frequent HO area to the fixed destination selected in step S43. As a result, the communication device 2 performs wireless communication only with the fixed destination in the frequent HO area in accordance with the received HO transmission control information.

[0142] According to the embodiment described above, the following effects are achieved.

[0143] The communication system 100 according to this embodiment is a communication system 100 equipped with a wireless communication unit 24 that is mounted on a vehicle 81 and that communicates wirelessly with a base station 72, and that generates planned route information regarding a route that the vehicle 81 is scheduled to travel based on input information, and includes a route information acquisition unit 104 that acquires the planned route information, a base station information acquisition unit 105 that acquires base station information including position information of each of a plurality of base stations 72 that cover the communication area of ​​the route included in the acquired planned route information, and a base station information acquisition unit 106 that sets the base station 72 to which the wireless communication unit 24 is currently connected as a connection destination for other wireless communication on the route included in the planned route information. The device includes an HO frequent area acquisition unit 107 that acquires information about an HO frequent area where handovers to be switched are expected to occur frequently, an arrival time prediction unit 108 that predicts the scheduled arrival time at which the vehicle 81 will arrive in the HO frequent area, and a communication setting unit 110 that sets the connection destination for wireless communication by the wireless communication unit 24, and the communication setting unit 110 fixes the connection destination for wireless communication that enables suppressing frequent handovers in the HO frequent area to a fixed connection destination, which is one connection destination, for the HO frequent area indicated by the HO frequent area information acquired by the HO frequent area acquisition unit 107, by the scheduled arrival time.

[0144] When a handover occurs, data transmission and reception is started after a connection is established between the communication device 2 of the vehicle 81 and the new wireless communication connection destination for transferring information, etc., and therefore there is a possibility that a delay in the data transmission speed will occur. If handovers occur frequently, the delay time will accumulate.

[0145] In this embodiment, the wireless communication connection destination in an area where HO occurs frequently is fixed to one, thereby avoiding frequent handovers, reducing data loss and delays in data transmission speed, and ensuring communication reliability.

[0146] In the communication system 100 according to this embodiment, the fixed connection destination fixed by the communication setting unit 110 is the base station 72 that is predicted to have the most number of wireless communication connections due to handover in the HO frequent area.

[0147] This fixes the connection destination to the base station 72 that is frequently the connection destination for handovers that occur in areas where HO occurs frequently, thereby avoiding the accumulation of communication delay time and maintaining more stable communication quality even in areas where HO occurs frequently.

[0148] In addition, in the communication system 100 according to this embodiment, the fixed connection destination fixed by the communication setting unit 110 is the base station having the strongest time average of the received radio wave strength received by the wireless communication unit 24 when wireless communication is connected in an area where HO occurs frequently.

[0149] This allows the system to connect to a base station with strong received radio wave strength when connecting wirelessly in an area where HO is frequent, thereby avoiding the accumulation of communication delay time and maintaining more stable communication quality even in areas where HO is frequent.

[0150] In addition, in the communication system 100 according to this embodiment, the fixed connection destination fixed by the communication setting unit 110 is the base station 72 that is predicted to have the smallest variation in the received radio wave strength received by the wireless communication unit 24 each time wireless communication is connected in the HO frequent area, among the base stations 72 that are predicted to repeatedly connect and disconnect wireless communication in the HO frequent area.

[0151] This reduces fluctuations in received radio wave strength in areas where HO is frequent, allowing the driver of the vehicle 81, etc., to more appropriately handle travel in areas where HO is frequent, where communication quality tends to be unstable, and ensures communication reliability.

[0152] In addition, in the communication system 100 according to this embodiment, the fixed connection destination fixed by the communication setting unit 110 is the base station 72 in the HO frequent area in which the wireless communication unit 24 is predicted to receive radio wave strength equal to or greater than a predetermined radio wave strength for the longest time.

[0153] This allows, for example, the base station 72 that is predicted to receive radio wave strength above the HO threshold for the longest time by the wireless communication unit 24 to be the fixed connection destination, thereby maintaining more stable communication quality even in areas where HO occurs frequently.

[0154] In the communication system 100 according to this embodiment, the fixed connection destination fixed by the communication setting unit 110 is a connection destination of a communication method in which handover does not occur in an area where HO frequently occurs.

[0155] This avoids delays in data transmission due to frequent handovers, and also maintains a certain level of communication quality in areas where handovers occur frequently and communication quality tends to become unstable.

[0156] In the communication system 100 according to this embodiment, the communication methods that do not involve handover are communication methods suitable for multi-access edge computing, such as V2I, V2V, and methods that use satellite communication.

[0157] This avoids delays in data transmission due to frequent handovers, and also maintains stable communication quality in areas where HO is frequent and communication quality is likely to become unstable, thereby ensuring communication reliability.

[0158] The communication system 100 according to this embodiment also includes an information processing device 1 having a route information acquisition unit 104, a base station information acquisition unit 105, a HO frequent area acquisition unit 107, an arrival time prediction unit 108, and a communication setting unit 110, and a communication device 2 having a wireless communication unit 24 that performs bidirectional communication with an external communication device 7 and the information processing device 1.

[0159] As a result, by separating the communication device 2 that performs wireless communication with the external communication device 7 and the like from the information processing device 1 that performs calculations using various information such as predictions of areas where HO occurs frequently and predictions of received radio wave strength, the processing of the communication device 2 can be specialized for wireless communication with the external communication device 7. This allows for smoother wireless communication and ensures more reliable wireless communication reliability even when the communication environment in an area where HO occurs frequently is degraded.

[0160] In addition, in the communication system 100 according to this embodiment, the information processing device 1 is capable of communicating with the communication device 2, an in-vehicle sensor 4 that detects movement information of the vehicle 81, an outside sensor 5 that detects the situation around the vehicle 81, and an HMI 3 that accepts input operations by the driver of the vehicle 81 and outputs information to the driver, and generates planned route information, predicts areas where HO is frequent, and predicts the planned arrival time based on the information acquired from the communication device 2, the in-vehicle sensor 4, the outside sensor 5, and the HMI 3.

[0161] This makes it possible to more accurately predict areas where HOs occur frequently, and more reliably maintain communication reliability even when the communication environment deteriorates.

[0162] In the communication system according to this embodiment, the HMI 3 accepts input operations by the driver of a plurality of point information used for generating planned route information by the information processing device 1, and transmits the information to the information processing device 1.

[0163] This makes it easier to create a planned driving route for the vehicle 81.

[0164] The program according to this embodiment is a program to be executed by the computers 16, 28 of the communication system 1 that is mounted on the vehicle 81 and has a wireless communication unit 24 that communicates wirelessly with a base station 72. The program includes a route information acquisition process that generates planned route information regarding the route along which the vehicle 81 is scheduled to travel based on input information, and acquires the planned route information; a base station information acquisition process that acquires base station information including the location information of each of the multiple base stations 72 that cover the communication area of ​​the route included in the acquired planned route information; an HO frequent area acquisition process that acquires information regarding an HO frequent area on the route included in the planned route information where handovers are expected to occur frequently, in which the base station 72 to which the wireless communication unit 24 is currently connected is switched to another wireless communication connection destination; an arrival time prediction process that predicts the arrival time at which the vehicle 81 will arrive in the HO frequent area; and a communication setting process that sets the wireless communication connection destination by the wireless communication unit 24. In the communication setting process, the wireless communication connection destination is fixed to one connection destination for the HO frequent area indicated by the information acquired in the HO frequent area acquisition process by the predicted arrival time.

[0165] The communication method of this embodiment is a communication method applied to a communication system 1 that is mounted on a vehicle 81 and has a wireless communication unit 24 that communicates wirelessly with a base station 72, and includes a route information acquisition process that generates planned route information regarding the route that the vehicle 81 is scheduled to travel based on input information, and acquires the planned route information; a base station information acquisition process that acquires base station information including location information of each of a plurality of base stations 72 that cover the communication area of ​​the route included in the acquired planned route information; an HO frequent area acquisition process that acquires information regarding an HO frequent area where handovers are expected to occur frequently on the route included in the planned route information, in which handovers that switch the base station 72 to which the wireless communication unit 24 is currently connected to another wireless communication connection destination are expected to occur frequently; an arrival time prediction process that predicts the arrival time at which the vehicle 81 will arrive in the HO frequent area; and a communication setting process that sets the wireless communication connection destination by the wireless communication unit 24, and in the communication setting process, the wireless communication connection destination is fixed to one connection destination for the HO frequent area indicated by the information acquired in the HO frequent area acquisition process by the predicted arrival time.

[0166] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate. [Explanation of symbols]

[0167] 1. Information processing equipment 2. Communications equipment 3. HMI 4 In-vehicle sensors 5. Outside vehicle sensors 8 Mobile 24 Radio Communication Department 72 Base station 81 Vehicle 100 Communication Systems 104 Route information acquisition unit 105 Base station information acquisition unit 107 HO frequent area acquisition unit (handover frequent area acquisition unit) 108 Arrival time prediction unit 110 Communication setting section

Claims

1. A communication system equipped with a wireless communication unit that is mounted on a mobile object and that wirelessly communicates with a base station, a route information acquisition unit that generates route information regarding a route along which the mobile object is scheduled to travel based on input information and acquires the route information; a base station information acquisition unit that acquires base station information including location information of each of a plurality of base stations that cover a communication area of ​​the route included in the acquired route information; a handover frequent area acquisition unit that acquires information on a handover frequent area in which handover, which switches a base station to which the wireless communication unit is currently connected to another wireless communication connection destination, is expected to occur frequently on the route included in the route information; and an arrival time prediction unit that predicts an arrival time at which the mobile object will arrive in the frequent handover area; a communication setting unit that sets a connection destination of the wireless communication by the wireless communication unit, A communication system in which the communication setting unit fixes the wireless communication connection destination to one connection destination for the handover frequent area indicated by the information acquired by the handover frequent area acquisition unit by the predicted arrival time.

2. 2. The communication system according to claim 1, wherein the one connection destination fixed by the communication setting unit is the base station that is predicted to have the most number of wireless communication connections due to handovers in the frequent handover area.

3. The communication system according to claim 1, wherein the one connection destination fixed by the communication setting unit is a base station in the handover frequent area having the strongest time average received radio wave strength received by the wireless communication unit when the wireless communication is connected.

4. The communication system described in claim 1, wherein the one connection destination fixed by the communication setting unit is a base station, among base stations that are expected to repeatedly connect and disconnect wireless communications in the handover frequent area, that is expected to have the smallest variation in the received radio wave strength received by the wireless communication unit each time wireless communications are connected in the handover frequent area.

5. The communication system described in claim 1, wherein the one connection destination fixed by the communication setting unit is the base station in the handover frequent area in which the wireless communication unit is predicted to receive a radio wave strength equal to or greater than a predetermined radio wave strength for the longest time.

6. 2. The communication system according to claim 1, wherein the one connection destination fixed by the communication setting unit is a connection destination of a communication method in which handover does not occur in the handover frequent area.

7. The communication system according to claim 6 , wherein the communication method that does not involve handover is a communication method suitable for multi-access edge computing, such as V2I, V2V, or a method that utilizes satellite communication.

8. an information processing device including the route information acquisition unit, the base station information acquisition unit, the handover frequent area acquisition unit, the arrival time prediction unit, and the communication setting unit; The communication system according to claim 1 , further comprising: a communication device having the wireless communication unit for performing two-way communication with an external communication device and the information processing device.

9. the information processing device is capable of communicating with the communication device, an in-vehicle sensor that detects movement information of the mobile body, an outside sensor that detects a situation around the mobile body, and an input / output device that accepts an input operation by a driver of the mobile body and outputs information to the driver; The communication system according to claim 8, wherein the route information is generated, the handover frequent area is predicted, and the arrival time is predicted based on information acquired from the communication device, the in-vehicle sensor, the outside-vehicle sensor, and the input / output device.

10. The communication system according to claim 9 , wherein the input / output device receives an input operation by a driver of a plurality of pieces of location information used in generating the route information by the information processing device, and transmits the information to the information processing device.

11. A program to be executed by a computer of a communication system equipped with a wireless communication unit that is mounted on a mobile body and that wirelessly communicates with a base station, a route information acquisition step of generating route information relating to a route along which the mobile object is scheduled to travel based on the input information and acquiring the route information; a base station information acquisition step of acquiring base station information including location information of each of a plurality of base stations that cover a communication area of ​​the route included in the acquired route information; a handover frequent area acquisition step of acquiring information on a handover frequent area in which handover, which switches a base station currently connected by the wireless communication unit to another wireless communication connection destination, is expected to occur frequently on the route included in the route information; an arrival time prediction step of predicting an arrival time at which the mobile unit will arrive in the handover frequent area; a communication setting step of setting a connection destination of the wireless communication by the wireless communication unit, In the communication setting process, a program fixes the wireless communication connection destination to one connection destination for the handover frequent area indicated by the information acquired in the handover frequent area acquisition process by the predicted arrival time.

12. A communication method applied to a communication system equipped with a wireless communication unit that is mounted on a mobile body and that wirelessly communicates with a base station, a route information acquisition step of generating route information relating to a route along which the mobile object is scheduled to travel based on the input information and acquiring the route information; a base station information acquisition step of acquiring base station information including location information of each of a plurality of base stations that cover a communication area of ​​the route included in the acquired route information; a handover frequent area acquisition step of acquiring information on a handover frequent area in which handover, which switches a base station currently connected by the wireless communication unit to another wireless communication connection destination, is expected to occur frequently on the route included in the route information; an arrival time prediction step of predicting an arrival time at which the mobile unit will arrive in the handover frequent area; a communication setting step of setting a connection destination of the wireless communication by the wireless communication unit, In the communication setting step, the wireless communication destination is fixed to one destination by the predicted arrival time for the handover frequent area indicated by the information acquired in the handover frequent area acquisition step.

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